WEDNESDAY, Sept. 18 (HealthDay News) -- Quality of surgical care is directly related to the likelihood of hospital readmission for additional surgery, according to researchers at the Harvard School of Public Health.

"We found that when it comes to surgery, high-quality hospitals -- those with the highest volume or lowest mortality rates -- have lower readmission rates," said the study's senior author, Dr. Ashish Jha, a professor of health policy at Harvard.

The study, which is published in the Sept. 19 issue of the New England Journal of Medicine, "shows that readmissions are probably being driven by complications that occurred in the hospital, and the better hospitals likely have fewer complications," Jha said.

The findings also support plans by the U.S. Centers for Medicare and Medicaid Services to add surgical conditions to its hospital readmissions penalty program, he said.

"A lot of us have been concerned about whether they were going to be penalizing good hospitals -- those with good outcomes -- or not," Jha said. "Our findings are reassuring, suggesting that surgical readmissions may be a reasonably good measure of hospital quality."

Readmissions for medical conditions such as heart failure and pneumonia can occur for other reasons, Jha said. They often are related to factors such as patient income and severity of illness, rather than care during the initial hospital stay.

Some hospitals have put into place systems and practices that reduce the risk of their surgical patients being readmitted, said Dr. Don Goldmann, chief medical and scientific officer of the Institute for Healthcare Improvement, in Boston.

Learning why and how these hospitals outperform others will be critical, Goldmann said.

"If hospitals performing very few surgeries do not have the volume required to create highly reliable care systems despite their best quality-improvement efforts, perhaps they should not be performing them," Goldmann said. "This is a provocative suggestion and deserves careful consideration before being implemented."

Nancy Foster, vice president of quality and patient safety policy at the American Hospital Association, said the study shows only an association between readmissions and volume, not a cause-and-effect relationship.

Foster wants to know what these higher-volume hospitals do that is different than hospitals doing fewer procedures. "We have identified smaller hospitals that are doing quite well," she said. "So what's the secret they're applying?"

It may be that hospitals that do many procedures have standardized their approaches to surgery, Foster said. "And in that process have made sure they are doing the recommended treatments every time," she said.

For the study, Jha's team used data from Medicare to calculate 30-day readmission rates for six surgical procedures, including coronary-artery bypass surgery, lung surgery, open and closed repair of abdominal aortic aneurysm, colon surgery and hip replacement.

Data were collected on nearly 480,000 patients discharged from more than 3,000 U.S. hospitals.

The researchers found that about one in seven patients were readmitted within 30 days. Hospitals that did the most procedures and had the lowest death rates also had much lower readmission rates than other hospitals. These factors are two well-established measures of hospital surgical quality, they said.

For example, hospitals that performed the most surgeries had significantly lower readmission rates (12.7 percent) than hospitals that did the fewest (16.8 percent).

Hospitals with the fewest deaths after surgery also had significantly lower readmission rates (13.3 percent) compared with hospitals with the highest death rates (14.2 percent), the researchers found.